Mr O'Rourke had suffered with addiction issues and was living in sheltered accommodation with his partner who was pregnant with their fourth child at the time of his death.

However, Fr Farrell told the congregation today it was important to remember Mr O'Rourke was "on the right path".

He condemned the recent outbreak of violence in the capital and quoted Archbishop Diarmuid when he said: "Could the repeated question of an innocent four year old child to her grieving mother, ‘Where’s Daddy?’ fail to touch even such hearts?"

He said; "Martin was a young man who had very little really in life, but who had life and had a loving fiancée, children and friends, only to be so callously and brutally robbed of everything.

"His one and only precious life has been taken. His family and friends’ loved one has been taken. His fiancée's husband-to-be has been taken.

"His children's daddy has been taken," he continued.

"Many have said that Martin was at the ‘wrong place at wrong time', but in the years ahead it will be important for his children to know that while he may have been at the wrong place, he was also on the right path.

"It will be important too, to hear and keep the family’s memories of the person they knew and loved."

Fr Farrell spoke of how breaking news on TVs and social media screens told the nation of a "shocking, frightening, and tragic shooting of an innocent bystander on a Dublin street" on April 14th.

"It happened in the early afternoon, in the Season of Easter, in the Jubilee Year of Mercy, and in the wake of the main 1916-2016 Centenary Commemorations," he said.

"Martin O’Rourke was that bystander, an innocent man, a homeless man, a man doing his best to overcome personal adversity, a family man, a daddy, a fiancé, a young 24 year old Traveller man."

He described Mr O'Rourke as having been "a loving child, very good natured, always very respectful, and generous" and shared a story of how he offered up his room to his aunt one night she couldn't get back into her own home.

"Without any prompting Martin stepped forward and said, ‘You can have my room aunt Biddy – but no smoking!! He was very particular about keeping his room, and also himself, spotlessly clean and tidy," he told the church.

Fr Farrell also said Mr O'Rourke was in the process of getting his life back on track after losing direction.

"Coming to his senses, realising his role as ‘Daddy’, Martin was looking ahead - proud of how he was doing, he had just gone back to adult education, next week he was due to begin a drug rehabilitation course, which was leading to a FÁS course and then a job, and then his and Angeline’s planning for an apartment, a family holiday, and for the arrival of their fourth child."

Martin's father-in-law Larry Power spoke to the Herald ahead of the young dad-of-three's funeral today.

"We would like to thank everyone for all of the support and the help that they have shown to the kids.

"We just want to say a big, huge thank you to the community in Sheriff Street on behalf of the family and Martin's three children. They've been very supportive, it's a very strong community down there," he said.

Following a public appeal for help covering the funeral costs for the Dublin man who was murdered in a case of mistaken identity, more than €5,000 flooded in.